It is known in the art to cut glass using a laser beam. For example, U.S. Pat. No. 3,930,825 to Chui describes cutting a molten glass ribbon using a laser beam while U.S. Pat. No. 3,453,097 to Hafner describes cutting a sheet of glass using several stationary laser beams which impact the glass at acute angles to produce a beveled edge.
The cutting of sheets of tempered glass however presents certain problems not found in the technology applied to the cutting of ordinary sheets of glass. Tempered glass while possessing greater strength in some respects than ordinary glass also has a greater tendency to fracture and shutter either from mechanical or thermal shock. Further, the application of heat to tempered glass may result in actually removing the temper from the glass in the localized area of heating. Accordingly, technologies which have found application in the treatment of ordinary glass have frequently not been useful in the treatment of tempered glass sheets.
It is therefore one object of the present invention to provide a method and apparatus for permitting the rapid and efficient cutting of sheets of tempered glass.
It is a further object of the present invention to provide a method and apparatus for cutting tempered glass using a moving laser beam whereby the temper of the glass is retained after the cutting operation.
Still a further object of the present invention is to provide a method and apparatus for cutting tempered glass which avoids the problem of shattering of the glass either from mechanical or thermal shock.